You talk about not putting words in anyone's mouth, and then you start off with assuming I was trolling and abusive (??) and reporting me, when I genuinely didn't know why you were talking about that? Really ******* nice, man.

Anyway, super scary turn 2 x/2's do not happen that often, and for things like Tarmogoyf we have blockers forever. But either way, I play 4 1-drop goblins and a Tarfire, and about half the time I can have one in play on turn 1 or Vial it in on T2. So about half that time, it is nice to be able to take out a creature that is x/2, or even flash block something like a Goblin Guide if needed.
And not killing a SFM on T2 doesn't get the game out of reach. We have so many different lines in which we can deal with a Batterskull, either by destroying it or blocking it for a while.

But I'm done with this. I'm trying to convey some points here, but if you react to people in this way then I don't want to be a part of that.

About Thoughtseize: you do not play it in your sideboard, so there should be no problem running Cavern, then. Also, "when it's good" is a very subjective, grey area kind of thing. It's all about percentages, and there's no "this is good and this is not" line in that.
I also disagree with you on that you say that Field and Cavern are fighting for the same space. Field is much more straining on our manabase, including casting any goblins like Warchief, who has double red in the cost, or casting multiple goblins in one turn with Warchief out. Cavern does not have that problem. If you want to add Fields, you don't have to cut Caverns.
Like I said before, UW Control is partially such a good matchup because of Cavern, and not being able to counterproof your Matron or Ringleader is going to make it much tougher than it should be.
I don't think Jinxed Idol is going to be very good, to be honest. I think cards like Dragon's Claw, Chalice of the Void (at least when you're running Caverns lol), and Collective Brutality are all more influential options, especially against Burn.
And well, don't forget that Skirk Prospector is a thing, and that you can play any of these cards on turn 2 with him. You can even drop him with Vial if you played that on turn 2.
Have you tried playing with Krenko? I hear a lot of people saying that it is a win-more card, but people who have actually played with it say that it is a really good card and that they underestimated it. It can win you games you have no business winning, and it has such strong synergies with so many goblins that we have. And you can also play around removal, Vial him in when your opponent is tapped out or when you have a Warchief in play.
I'd say try him for a while, and see what you think after you've played him a number of times.

Also, you completely ignored everything Ace1 said about your mention of redundancy and the arbitrariness of the 90% line, just to hammer about how Munitions Expert isn't that good or something? I don't really know what you're trying to say there.
Being able to play a Sling-Gang and an Expert, or two Experts on one turn, or a turn 2/3 Earwig Squad, are all relying on the manabase being consistent, not just a turn 2 Expert.

The only black card you're playing that cannot be cast with Cavern of Souls is Warren Weirding. To make your deck more inconsistent and more painful, only to up the consistency of one sideboard card, seems like a very wrong choice to make. The downside here is much bigger than the upside.
An argument can be made to play 3, maybe even 2, but even then it's pretty iffy and just not as optimal in most cases as playing 4 Caverns.

What you said about counterspells is simply not right. Counterspells, and blue in general, is really strong right now, and cards like Logic Knot, Mana Leak and Cryptic Command are definitely out there. Also, Chalice of the Void is not a problem for us at all, since it mostly only counters Vial and Tarfire, and if we ourselves run Chalice it enters after Vial anyway.

I don't know which lands you specifically added instead of Cavern, but if I were to add them I would cut 1 Field of Ruin, 1 Wooded Foothills and 2 Sunbaked Canyon. That already is 3 lands that hurt a lot more than 0 life. Cutting the 4th Field also makes you more consistent in general, as you then will have a much lower chance of having 2 Field in your opening hand.

Just saying that we will probably lose to an unanswered Eidolon is not really an argument. You yourself said that you usually have 1-2 Burn players in your LGS, and I assume you are not just giving up that matchup. Since that can be a tough match, you want to be as prepared for that as possible.
Making yourself not lose much life from your own lands is a very easy way to improve not only your Burn matchup, but also others.

Also, we are one of the best decks to outgrind our opponent with insane card advantage, where we can also dump our hand really fast in the midgame with Skirk Prospector, Goblin Warchief and Aether Vial. Isn't it better to have something like Krenko, Mob Boss in your sideboard? That way you can keep your Ringleaders as strong as possible, while also being able to overwhelm your opponent with a card you can Matron for? (This is just a suggestion though.)

This is going to be a pretty short reply, but I don't think you can dismiss Cavern of Souls that easily. You now have at least 2 more lands that don't make black mana, which can make certain hands needlessly awkward. The can't be countered clause literally has no downside, and making a specific matchup really good (UW Control) is very good for us. Another point that I think is very important and didn't see you talk about is life. Our Burn matchup isn't that great, and when you are playing 4 extra lands that cost you life in an otherwise relatively painless manabase, that will probably cost you a significant amount of win percentage against Burn, where (at least against us) games can be very close and every point of life can make a difference.

Also, why are you running 1 Abrade in your sideboard? Goblin Cratermaker and Kolaghan's Command both seem a lot better.
And why the Chandra? What does it do better than other sideboard cards, that we need in Goblins?

They are too slow, don't guarantee the discard, and doesn't look at the opponent's hand or let you choose which card to discard. Use Thoughtseize instead. 3 in your sideboard makes them appear in your opening hand often, and playing it on the first turn helps a lot to buy us time against most unfair decks.

If you have played with Piledriver a long time ago, then the meta must have been different from what it is now. I know that Hogaak will definitely be banned, causing a shift in the meta really soon, but there are other decks now that didn't exist back then (Phoenix and Thopter being the newest additions). So comparing your past experiences with the current ones is not an equal comparison.

The power of him isn't that he can't be removed by blue spells (although that does help against UW Control, where they cannot bounce it with Cryptic Command, Jace, The Mind Sculptor or either Teferis) or that he can't be countered (he can indeed be countered, but counterspells are notoriously bad against us,because we run Aether Vial and Cavern of Souls); he is really good because he is a big threat, and needs to be answered. And when the opponent chooses to remove a Piledriver, that is one removal spell they cannot use on Matron or Ringleader.

What I was saying is that in the decks I mentioned, there are only very few creatures that can block Piledriver, and even if they happen to have one of those, we have Munitions Expert, Pashalik Mons, Tarfire, Mogg Fanatic and/or Cratermaker as removal, so we can swing through with a 11/2. And if they are a deck that play few big creatures, they would either have to block with something like a Reality Smasher, Primeval Titan, or Tarmogoyf, or take a lot of damage. This also makes it so that other goblins (like Warchief) have a bigger chance of not getting blocked/killed in combat.
As for Plague Engineer: when the opponent plays it, our main concern is getting rid of it, not getting in with Piledriver, so that argument is a bit loose. Any Goblin that survives that semi-sweeper is a big plus for us.

We are not an aggro deck, and we do not want to attack every turn. We are only going to attack when a) the opponent has no creatures and/or we need to race, or b) if we can win. Getting in with Piledriver is not our main way of winning (that would be swinging with (almost) everything and saccing it post combat with Sling-Gang), but it is a really good plan B that we can Matron for to swing for lethal out of nowhere.

Note that a big upside for Piledriver is that you can Vial it in at the end of your opponent's turn, and you can also give it haste with Warchief. This can make for some surprise attacks that the opponent didn't see coming (and didn't leave blockers open for). Also important: having multiples is insanely strong in almost all matchups.

It helps us race against a lot of the top decks that are being played right now: Tron, UR Phoenix, Dredge, Storm, Spirits, Humans, UW Control, Valakut, Burn, and Thopter. It also survives more than most our goblins do: Wrenn and Six, Lava Dart, Gut Shot, Plague Engineer, or being blocked by 1/1's.

Another thing I'd like to add is that I've seen and talked to a number of other Goblins players, and they all play 2-3 Piledrivers, with good results and a really positive view on the card.

And to answer the last part of your response: the purpose of Piledriver is to race your opponent. Goblins is a control-combo deck, and generally gets outraced by decks like Burn or fast combo decks. Piledriver helps combat those decks, making our bad mautchups better.
A more subjective thing, but: I would cut one Frogtosser Banneret and 2 Chieftains, or one Frogtosser, one Chieftain, and either one Tarfire, Pashalik Mons, or Skirk Prospector.

And to explain a bit about Chieftain, which links nicely with The Fluff's question:
Like I said before, Goblins is not an aggro deck. A lot of people make that mistake, but it is actually combo-control (for the lack of a better term for such a versatile deck). We want to block our opponent's creatures forever with Mogg War Marshal, Goblin Matron etc, draw cards forever (which is THE reason to play this deck; no other deck can grind like we can), and win in one turn with an alpha strike + Sling-Gang.
Therefore, Chieftain isn't that good. He can pump our board, but if he gets removed during combat it can create an awful blocking scenario for us. It also doesn't protect our board against Plague Engineer: Jund right now is the biggest deck that runs PE, sometimes even mainboard, and Chieftain creates a house of cards like state, where only 1 damage to your Chieftain will cause it and all your pumped 1/1's to be gone.
This is also why Piledriver is generally better: He gets the boost at the start of attackers phase, and what happens to the rest doesn't matter. If Piledriver gets removed during combat, the rest of the attackers stay the same, something which you can rely on.
Trashmaster is a very strong sideboard card, but I don't think it's wanted/needed in the main.

Note that there is no 'average' Goblins list. Because Goblins is partially a control deck, we have to change when the meta changes.
Some things that deviate the most from other decks (even though my deck is a pretty average list):
The amount of Skirk Prospectors (0-4), Mogg Fanatics (0-4), and Legion Loyalists (0-1)
The amount of Frogtosser Bannerets (0-4), Goblin Cratermakers (0-2), Sling-Gangs (1-2) and Krenko's (0-1)
The amount of lands (22 or 23), the amount of Field of Ruins (0-4), the amount of Swamps (0-1)

Other sideboard cards that you can use are:
Damping Sphere
Chalice of the Void
Leyline of the Void (even though I don't think it's needed after the ban)
Surgical Extraction
Warren Weirding x1
Stingscourger x1
Another Pashalik Mons (so you have 2 total, helps against Humans)
Goblin Ruinblaster

I would strongly disagree, and say that playing 3 Piledrivers is not a bad option at all.
The protection from blue is very relevant, making you able to race decks like Dredge (Amalgam and Narcomoeba can't block), Urza Thopter (the thopters are blue), UR Phoenix (Thing in the Ice), Storm (both creatures can't block), and makes your UW Control matchup even better. It's pretty strong against any combo deck, which is one of Goblins' weaknesses. Also doesn't die to Plague Engineer, which is an important upside as well.
They have to be blocked most of the time, which makes them act like a removal spell which is also a creature. It's completely nuts with Warchief.
Edit: I would still play a Tarfire as well, pretty good Matron target if you need it and decent extra removal.

Like AmicDeep said, how is the lack of Scavenging Ooze? You only have one in your side.

One of my biggest questions is regarding the lack of Aspect of Hydra. One of the deck's biggest strengths is the ability to close down matches one turn faster with the use of Aspect, that would otherwise be a lot more difficult to win by giving the opponent an extra turn (like against Burn, Storm, Scapeshift, etc). This is one of THE reasons to play this deck, and has been said for a long time. Not being able to alpha strike through you opponent's board and playing Aspect on the unblocked attacker is something I would really miss while playing. How are you finding playing without it? I personally think Hunger of the Howlpack is not as good by far: even though it is permanent, only being able to give a creature +3/+3, and that only being after a creature has died (so most likely after combat) seems really suboptimal and will make you play a longer game than usual.

Other questions: Why have you not upgraded the manabase? Is it a budgetary issue? Even if you're not playing fetches, I would really suggest playing 2 Nurturing Peatland. Other than that, what about other utility lands like Hashep Oasis or Tranquil Thicket?

Can you tell more about Savage Swipe? we have almost no information on the card, and I'm really curious to how good it is etc. Is it really that good? Wouldn't you rather have a 2/2 split with Dismember?

I would say that your list looks pretty good, but I would make place for the last 2 Dryad Militant. That card does a lot of work against a significant amount of decks. Also change the Waterlogged Grove to Nurturing Peatland if you're able. You might also want to play a Path to Exile or two main. The sideboard is pretty meta dependent, so I can only say play a lot of matches! That will also help you get a feeling of how many 1, 2 and 3-drops you want to play.

Please check it out! If you see any mistakes or text that should be updated/added, let me know!
Also, 2 out of the 6 cards depicted in the banner at the top of the primer are now obsolete..
Also also, Nurturing Peatland will not show the card when I hover over it with my cursor, but all the other new card do work. Does anyone know why this is?

I'm planning to update the primer with Hexdrinker, as well as some other cards, and these are my findings so far (mostly just info about the card, but I thought people would still like to see it):

It's good no matter which version you're running, I would start with running 2, and 3 or 4 might be optimal in a fetchless build but I am not sure on it yet (it's not that good in multiples, and in fetch builds you already have Dryad Militant and Narnam Renegade). Note that you cannot pump your Hexdrinker after it gets protection from instants, but Rancor is still fine, as long as it does not have protection from everything. Leveling it up to that while Rancor is on it will make it fall off, and go to the graveyard (and then back to your hand). It will also be good to have Vines of Vastwood open when you level it to level 3; that way the opponent has only one moment to kill it before all spot removal becomes useless against it. Note that Hexdrinker can always die due to a sacrifice effect, getting mass -X/-X or just -1/-1 counters, or mass exile effects like Settle the Wreckage (since it doesn't destroy). When it has protection from instants, most mass removal like Wrath of God, Supreme Verdict, Anger of the Gods and Damnation are sideboard cards you need to look out for, since they are usually boarded in against us.

I put it in bold somewhere at the top of the primer, and like you said as well: do not suggest 4 drops. It's as simple as that. It has to single handedly win us the game on the spot if we want to run it, or it'd be a sideboard card that wrecks specific decks. Only two cards have really made it into the sideboard: Thrun, the Last Troll against Control, and Creeping Corrosion against Affinity (and not even everyone runs those). Other than that, 4 drops are just not for us.

Dungrove Elder relies on Forests, so people who play that can argue against it.
Also, people who are not on a budget should run Horizon Canopy or Nurturing Peatland over Hashep Oasis (by the way everyone, if you're not splashing white you should run Peatland because it has the very slight upside of making Dismember cost 1 less life sometimes).
We also only run 2 Canopy lands; some people might argue for 3 (which I would not recommend), but definitely not more than that.
The reason for that is that you do not want to hurt yourself so often, especially when you have 2 of them in your opening hand. This is very relevant against a number of decks, most notably Burn and other aggro decks that want to outrace you. Also decks like Storm and Scapeshift might be able to go off earlier if you have damaged yourself for about 5 life throughout the game.
Short answer: we kind of do care about our life total, especially since Stompy is not as strong in the meta as it used to be.

It's not good to play on turn 1, not even turn 2. It only has 1 power, which is a red flag for our deck.
You need to have 3 lands in your graveyard, which means you need to crack 3 fetches/canopy lands before this card gets good.
His ability is not useful for us. It costs 2 mana, which is a lot for us, and if you want to use his ability to turn his first ability on, you still can't use him to attack since you need to tap him as well.
We have no real utility lands that we could search for.
In conclusion: I think he's too slow. Even if he is not awful as a topdeck late game, Hexdrinker is better in basically every way.